Technical Field
The present invention relates to a wind turbine rotor blade, to a connecting device for connecting a rotor-blade inner portion to a rotor-blade outer portion of such a rotor blade, and to a wind turbine. The present invention additionally relates to a method for connecting a first rotor-blade portion to a second rotor-blade portion.
Description of the Related Art
Wind turbines are known in general and are designed, for example, as in FIG. 1. In particular, the size of the rotor blade, or blades, is an important aspect for the efficiency of a wind turbine. In order then to achieve a sufficiently high wind turbine efficiency even in the case of light winds, wind turbines nowadays have increasingly larger rotor diameters, and thus also longer rotor blades. Such a rotor blade, for example, has a length of 40 m or more. With such sizes, it is proving increasingly difficult to manufacture these rotor blades, transport them to the installation site and mount them on the rotor hub of the wind turbine at the installation site. In order to avoid these problems, rotor blades that have a divided rotor blade are already known. The rotor blade in this case is sub-divided, at least in the rotor-blade longitudinal axis, into two parts, namely, into an inner part, the rotor-blade inner portion, which is attached to the rotor-blade hub, and into an outer part, the rotor-blade outer portion, which has a rotor-blade tip.
Such rotor blades, divided in the direction of the rotor-blade longitudinal axis, have connecting devices for connecting the rotor-blade inner portion to the rotor-blade outer portion. The connecting devices in this case are provided at projecting webs or similar. As a result of this, a force acting at the individual rotor-blade portions is deflected into the projecting webs, such that there are unfavorable force conditions acting at the connecting point. These unfavorable force conditions cause local bending moments, which may result in damage at or to the connecting point. Moreover, such connecting devices are usually attached to the rotor blades following the manufacture of the individual rotor-blade portions, such that, in order to attach the connecting device in the respective rotor-blade portion, it is necessary for material to be removed from the rotor blade. Frequently in such cases, to enable precise work to be performed, expensive machines or appliances are required. Moreover, the retroactive fitting of the connecting devices often requires a large amount of time, with the result that the erection of the entire wind turbine is delayed. Thus, the connections known hitherto prove to be expensive and time-consuming.
In the German patent application establishing priority, the following documents were searched by the German Patent and Trademark Office: EP 2 735 732 A2; DE 10 2013 205 965 A1; DE 38 79 287 T2; DE 10 2010 039 778 A1; EP 2 031 245 A2; DE 693 078 56 T2 and DE 695 347 67 T2.